Ear wax guard

ABSTRACT

To prevent soiling of a hearing aid, the latter is provided with an exchangeable ear wax guard which, in the area of the sound outlet opening of the hearing aid, can be inserted into a sound tube. The ear wax guard is characterized in that, in order to improve its securing in the sound channel, it is provided with elevations at least in a subarea of its surface. On the surface of the ear wax guard, the density or size of the elevations preferably increases counter to the direction of insertion of the ear wax guard.

BACKGROUND OF THE INVENTION

The invention relates to an ear wax guard for a hearing aid whichcomprises at least a microphone, an amplifier unit and a receiver, inwhich sound signals picked up by the microphone are amplified in theamplifier unit, are converted into acoustic signals by the receiver, andare delivered via a sound channel to the eardrum, and in which the earwax guard can be fitted entirely or partially into the sound channel.

International Patent Publication WO99/07182 A2 discloses an acousticcoupler with an ear wax guard. On assembly of the coupler, a receiver ismounted in a housing which is provided with a thread or a toothedsurface and in this way can be screwed into the coupler or can be lockedin notches of the coupler.

International Patent Publication WO 00/03561 discloses an ear wax guardwhich can be inserted into the sound outlet opening of a hearing aid andcan be removed from this again for replacement. The ear wax guard has asubstantially cylindrical outer shape and is provided with a bead viawhich the ear wax guard is secured in a sound tube. A disadvantage ofthis securing method is the non-uniform force which is exerted on thesound tube upon insertion of the ear wax guard into the sound tube andupon its removal therefrom. In the least favorable scenario, this canlead to the sound tube coming loose from the housing of the hearing aidin the area of the sound outlet opening. Moreover, the bead can lead toa kind of memory effect in the sound tube. In this way, there is apermanent deformation of the sound tube in the area of the bead.However, this impairs the securing of the ear wax guard in the soundtube and can even lead to its loss.

U.S. Pat. Nos. 5,864,628 and 5,712,918 disclose ear wax guards which, inthe area of the sound outlet opening of a hearing aid, can be insertedinto and removed from a sound tube. The front end of the known ear waxguard narrows in a frustoconical shape, which makes it easier to insertthe ear wax guard into the sound tube. Moreover, the front end has agreater diameter than the remaining part of the ear wax guard to beinserted into the sound tube. In this way too, as in the above-mentionedpublication WO 00/03561, a kind of bead is formed which engages in thesound tube and secures the ear wax guard in the sound tube. Therefore,the disadvantages mentioned for publication WO 00/03561 also arise inthis case.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new design for thesecuring of an ear wax guard in the sound channel of a hearing aid.

In an ear wax guard for a hearing aid which comprises at least amicrophone, an amplifier unit and a receiver, in which sound signalspicked up by the microphone are amplified in the amplifier unit, areconverted into acoustic signals by the receiver and are delivered via asound channel to the eardrum, and in which the ear wax guard can befitted entirely or partially into the sound channel. This object isachieved by the fact that a surface of the ear wax guard for securing inthe sound channel is provided with a plurality of elevations which lieon a smooth surface of the sound channel and, as a result of friction,generate a holding action.

According to the embodiments of the invention described below, the earwax guard is preferably of cylindrical design and is provided with athrough-hole, so that the sound generated by the receiver can beconducted through the sound channel and the ear wax guard to theeardrum. Arranged in the through-hole there is advantageously an ear waxretainer which, for example, can be designed as a grate structure or asa disk-shaped element with a plurality of smaller through-openings. Inaddition to the function of protecting the receiver from soiling, theear wax guard can also perform an acoustic function as an attenuator, inwhich case the sound-attenuating effect can be influenced in particularby the choice and arrangement of the elements, such as the ear waxretainer, located in the through-hole. The ear wax retainer can bedesigned for complete or partial insertion into the sound channel, andin the latter case its diameter at the rear end preferably increases insuch a way that complete insertion into the sound channel is prevented.

The invention has the advantage that the force to be applied wheninserting the ear wax guard into the sound tube increases continuouslyand uniformly until the ear wax guard has finally reached its endposition. This prevents the sound tube coming loose from the housing ofthe hearing aid in the area of the sound outlet opening. In addition, itis very unlikely that, upon removal and reinsertion of the ear waxguard, the elevations will come to lie at the same position again. Inthis way, a memory effect is avoided, and the ear wax guard remainsfirmly secured in the sound channel even after quite a long period ofuse.

A special arrangement or design of the elevations can also be used toinfluence the force applied when inserting the ear wax guard into thesound tube. Thus, in one embodiment of the invention, the density of theelevations, along the insertable housing area, increases counter to thedirection of insertion. This means that, in the front area of the earwax guard inserted first into the sound channel, there are fewerelevations than in a rear area of the ear wax guard. The force to beapplied for inserting the ear wax guard thus increases uniformly.

In another embodiment of the invention, the height of the elevationsvaries between the front area and the rear area of the ear wax guard. Inthe front area inserted first, the height of the elevations iscomparatively low in relation to the height of the elevations in therear area. In this way too, it is possible to obtain a constant increasein the force to be applied upon insertion of the ear wax guard.

A combination of the two last-mentioned embodiments is also possible.Thus, in a front area of an ear wax guard according to an embodiment ofthe invention, both the density of the elevations and the height of theelevations can be low by comparison with an area lying farther to therear. In this way, an even steeper force profile is obtained, i.e., agreater increase in the force to be applied during insertion of the earwax guard into the sound channel.

A situation in which the ear wax guard falls out of the sound channelwhen the hearing aid is being worn must absolutely be avoided, becausein some circumstances it can be removed from the auditory canal onlywith difficulty. For this reason, one embodiment of the inventioninvolves specially shaped elevations which ensure that the force to beapplied for inserting the ear wax guard into the sound channel isrelatively low compared to the force for removing the ear wax guard fromthe sound channel. This is achieved, for example, by the fact that,starting from the normal surface of the ear wax guard, the elevationsrise gradually and constantly, counter to the direction of insertion,and then fall back abruptly from the maximum height of the elevations tothe normal surface level. The elevations can also have a design taperingin the direction of insertion. Thus, for example, the elevations have asemi-conical design, the tip of the cone pointing in the direction ofinsertion.

DESCRIPTION OF THE DRAWINGS

The invention is described below on the basis of illustrativeembodiments shown in the drawings.

FIG. 1 is a section view showing the front end of an in-the-ear hearingaid, and an ear wax guard according to the prior art, along with a graphshowing the relationship between force and distance;

FIG. 2 is an isometric view showing the ear wax guard according to theprior art;

FIG. 3 is a section view showing the front end of a hearing aid, and anear wax guard according to the invention, along with a graph showing therelationship between force and distance;

FIG. 4 is an isometric view showing the ear wax guard according to FIG.3 with triangular elevations;

FIG. 5 is an isometric view showing an ear wax guard with ovalelevations; and

FIG. 6 is an isometric view showing an ear wax guard with roundelevations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the front, proximal end of an in-the-ear hearing aid, andan ear wax guard according to the prior art. The in-the-ear hearing aid1 comprises a housing 2 with a sound outlet opening 3 arranged in thehousing. Arranged inside the housing 2 there is a receiver 4 which isconnected to the sound outlet opening 3 via a sound tube 5. In the areaof the sound outlet opening 3, the sound tube 5 is usually secured onthe housing 2 of the hearing aid 1 via a securing mechanism, forexample, an adhesive 6.

To protect the hearing aid 1 from soiling, an ear wax guard 7 isprovided which can be inserted partially into the sound tube 5. This earwax guard is of substantially tubular design, so as to be able toconduct the sound from the receiver 4 into the auditory canal of ahearing aid wearer. The external diameter of the tubular ear wax guard 7corresponds approximately to the internal diameter of the sound tube 5.In order to prevent penetration of wax into the hearing aid 1, the earwax guard 7 comprises, in its inside, a grate structure 8 with smallsound passages. A collar 9 is formed integrally on the outer end of theear wax guard 7, this collar 9 preventing complete insertion of the earwax guard 7 into the sound tube 5. If appropriate, a suitable tool forwithdrawing the ear wax guard 7 from the sound tube 5 can also beattached to this collar 9.

An inserted ear wax guard 7 must be secured on the hearing aid 1, and inparticular on the sound tube 5, in such a way that inadvertentseparation from the hearing aid 1 can be ruled out under normalcircumstances. For this reason, the ear wax guard 7 is provided with acircumferential bead 10, so that a friction connection with the soundtube 5 is obtained.

In the diagram associated with FIG. 1, the force F needed for insertingthe ear wax guard 7 into the sound tube 5 is plotted along the distanceS. The abrupt increase in the force S, in the area in which the bead 10reaches the sound tube 5, is quite apparent. This force profile alsomore or less applies, in the reverse direction, upon removal of the earwax guard 7.

A disadvantage of this arrangement is the abrupt increase in force inthe area where the bead 10 reaches the sound tube 5. In the mostunfavorable scenario, this can lead to the sound tube 5 coming loosefrom the housing 2 of the hearing aid 1 in the area of the sound outletopening 3, for example by separation of the adhesive connection 6. Afurther disadvantage of this arrangement is that the bead 10 alwayscomes to lie at the same position in the sound tube 5 when the ear waxguard 7 has been inserted, and this results in a permanent deformationof the sound tube 5 at this position (memory effect).

FIG. 2 shows the ear wax guard 7 according to the prior art in athree-dimensional isometric view. The cylindrical surface is providedwith a circumferential bead 10 which is used to secure the ear wax guard7 in the sound tube 5. FIG. 2 also shows the collar 9 for preventingcomplete insertion into the sound channel, and the through-hole 11.

Like FIG. 1, FIG. 3 also shows the front, proximal part of an in-the-earhearing aid 21 with a housing 22, a sound outlet opening 23 in thehousing, a receiver 24 arranged inside the housing 22, and a sound tube25 for connecting the receiver 24 to the sound outlet opening 23. Heretoo, the sound tube 25 can be secured on the housing 22 by an adhesiveconnection 26.

The illustrative embodiment of the invention according to FIG. 3 alsocomprises an ear wax guard 27 which can be inserted to a large extentinto a sound tube 25. In contrast to the prior art according to FIG. 1,that part of the surface of the ear wax guard 27 inserted into the soundtube 25 is provided on its surface with elevations, the cross-sectionalview in FIG. 3 indicating elevations 30A–30F. The elevations accordingto the illustrative embodiment are distributed irregularly across thesurface of the ear wax guard 27. Moreover, the elevations 30A and 30D inthe front area of the ear wax guard 27, which is inserted first into thesound tube 25, are of a smaller size than the elevations 30C and 30F inthe rear area of the ear wax guard 27. In addition, the density of theelevations, relative to the surface of the ear wax guard 27, is lower inthe front area than in the rear area. This special configuration of thesurface of the ear wax guard 27 means there is an almost linearlyincreasing profile of the force required for inserting the ear wax guard27 into the sound tube 25 along the distance S. A corresponding forceprofile is likewise shown in FIG. 3. In this way, it is possible toavoid an abrupt increase in force which could lead to loosening of theadhesive connection 26. Moreover, the irregular arrangement of theelevations means it is very unlikely that these will again come to liein their previous position upon exchange of the ear wax guard 27. Apermanent deformation of the sound tube 25 is thus avoided.

FIG. 4 shows the ear wax guard according to FIG. 3 in athree-dimensional view. The figure shows the substantially tooth-likedesign of the elevations 30, with a triangular base surface and a pointoriented in the direction of insertion. Both the size and the density ofthe elevations 30 on the surface of the ear wax guard increase counterto the direction of insertion. The elevations 30 in the illustrativeembodiment are designed in such a way that they begin at the level ofthe surface of the ear wax guard 27 and gradually rise and become widerin the direction toward the rear end of the ear wax guard 27, then fallback abruptly to the starting level. The elevations narrow in thedirection of the front end of the ear wax guard. This design has theadvantage that the force to be applied for inserting the ear wax guard27 into the sound tube 25 is less than that for removing it. In thisway, insertion is made easier, and inadvertent loosening of the ear waxguard from the sound tube 25 is prevented.

In contrast to the last-mentioned illustrative embodiment, in which boththe density and also the size of the elevations 30 increase in the reararea of the ear wax guard, the elevations can, of course, also be of thesame size and only increase in the rear area in terms of their density,or increase only in terms of their size while retaining the samedensity.

Furthermore, both the density and the size of the elevations can remainthe same in the whole area to be inserted into the sound tube. FIG. 5shows one possible example of this. The ear wax guard 47 shown here,with a through-hole 51 and a collar 49, has oval elevations 50 whoselongitudinal direction extends parallel to the direction of insertion.The elevations in this illustrative embodiment are distributed randomlyon the surface, but with approximately uniform density. Moreover, allthe elevations 50 are at least approximately the same size.

A further illustrative embodiment is shown in FIG. 6. Here, an ear waxguard 67, with a through-hole 71 and a collar 69, has round elevations70 which are likewise distributed irregularly on the surface. Thedensity of the elevations 70 increases in the rear area of the ear waxguard. A further particular is that the ear wax guard 67 is providedwith a bow 72 into which a tool can engage for withdrawing the ear waxguard from a sound channel.

The invention is not limited to the illustrated shapes and arrangementsof the elevations. For example, the elevations can also be ofsemispherical design or of any other configuration. In addition, theelevations can also be arranged regularly on the surface of the ear waxguard, for example along straight lines. It is also possible that theear wax guard has no collar and can be inserted completely into thesound channel.

For the purposes of promoting an understanding of the principles of theinvention, reference has been made to the preferred embodimentsillustrated in the drawings, and specific language has been used todescribe these embodiments. However, no limitation of the scope of theinvention is intended by this specific language, and the inventionshould be construed to encompass all embodiments that would normallyoccur to one of ordinary skill in the art. The particularimplementations shown and described herein are illustrative examples ofthe invention and are not intended to otherwise limit the scope of theinvention in any way. For the sake of brevity, conventional aspects maynot be described in detail. Furthermore, the connecting lines, orconnectors shown in the various figures presented are intended torepresent exemplary functional relationships and/or physical or logicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships, physical connectionsor logical connections may be present in a practical device. Moreover,no item or component is essential to the practice of the inventionunless the element is specifically described as “essential” or“critical”. Numerous modifications and adaptations will be readilyapparent to those skilled in this art without departing from the spiritand scope of the present invention.

1. An ear wax guard for a hearing aid, the hearing aid comprising amicrophone, an amplifier unit and a receiver, in which sound signalspicked up by the microphone are amplified in the amplifier unit, areconverted into acoustic signals by the receiver and are delivered via asound tube to the eardrum, and in which the ear wax guard can be fittedentirely or partially into the sound tube, the ear wax guard comprising:a surface of the ear wax guard for securing in the sound tube having aplurality of elevations which lie on a smooth surface of the sound tubehaving a frictional fit to generate a holding action, the plurality ofelevations defining a means for continuously increasing a force ofinsertion as the ear wax guard is moved into the sound tube.
 2. The earwax guard as claimed in claim 1, wherein the elevations are distributedirregularly on the surface.
 3. The ear wax guard as claimed in claim 1,wherein a density of the elevations on the surface increases in adirection counter to a direction of insertion.
 4. The ear wax guard asclaimed in claim 1, wherein a size of the elevations on the surfaceincreases in a direction counter to the direction of insertion.
 5. Theear wax guard as claimed in claim 1, wherein the elevations are formedasymmetrically in such a way that, starting from a bottom level of thesurface of the ear wax guard, the elevations each gradually rise,counter to a direction of insertion, to a maximum elevation height andthen fall back abruptly to the bottom level of the surface.
 6. The earwax guard as claimed in claim 5, wherein the elevations have asubstantially triangular base surface, a point of a triangle in eachcase being oriented in the direction of insertion.
 7. The ear wax guardas claimed in claim 1, wherein the elevations have a substantially roundouter shape.
 8. The ear wax guard as claimed in claim 1, wherein theelevations have a substantially oval outer shape.
 9. The ear wax guardas claimed in claim 1, further comprising: a bow which is mountedintegrally on a rear end of the ear wax guard, in relation to thedirection of insertion, and on which a tool can engage in order towithdraw the ear wax guard from the sound tube.
 10. A hearing aidcomprising: a microphone; an amplifier unit; a receiver, in which soundsignals picked up by the microphone are amplified in the amplifier unit,are converted into acoustic signals by the receiver and are deliveredvia a sound tube to the eardrum; and an ear wax guard that can be fittedentirely or partially into the sound tube, the ear wax guard comprising:a surface of the ear wax guard for securing in the sound tube having aplurality of elevations which lie on a smooth surface of the sound tubehaving a frictional fit to generate a holding action, the plurality ofelevations defining a means for continuously increasing a force ofinsertion as the ear wax guard is moved into the sound tube.